On smartphones the menu takes 50% of screen, when there’s enough space for some of menu options to be in one row, rather than one below the other.
I’ve tried to fix it (playing with xs-col-* and display: inline-block; ) but failed, so I made a little hide button in jQuery as a workaround, so the page is readable. However it doesn’t make a good impression when you open it on small screen.

Other than that I think it’s working properly. Please share your feedback.